Sealing system for collapsible tubes and machine

ABSTRACT

Sealing System for Collapsible Tubes and Machine, consisting of: a plug ( 1 ) and a ring ( 2 ) which are placed at the bottom of a rigid, semi-rigid or soft collapsible tube ( 3 ) through a Machine or Tube-Holder ( 7 ), so that the tube will remain vertical during storage and use, always keeping its shape.  
     The plug ( 1 ) is a cylindrical body with a small circular tab ( 4 ) at the top, a central section ( 5 ) or plug proper, which is a hollow conical trunk or hollow cylinder; and a lower section ( 6 ) which is a conical trunk or solid cylinder.  
     The Machine or Tube-Holder ( 7 ) has five parts, as follows: a) a spring ( 8 ); b) a fixing housing ( 9 ); c) a base to hold the spring ( 10 ); d) a base to support the tube ( 11 ); e) a guide to fit the tube ( 12 ).

FIELD OF THE INVENTION

This Application for a Patent of a Utility Model refers to a Sealing System for Collapsible Tubes and Machine, which consists of a compound plug which is inserted into the lower part of the tube so that the tube is held vertical during storage and use, always maintaining the shape of the tube. The Application also refers to a Machine or Tube-Holder made especially for the process for Sealing the Tubes.

BACKGROUND OF THE INVENTION

At present, the sealing or plugging of collapsible tubes depends on the material of the tube, as described below:

In aluminium collapsible tubes sealing is achieved by folding as illustrated in FIG. 1, and as described in U.S. Pat. No. 4,196,825 entitled “Laminated Collapsible Tube” in the name of Colgate Palmolive Company Publisher on Apr. 8, 1980, which describes a Collapsible Tube used for toothpaste which has in its base a sealed articulated zone and a section in the form of a nozzle. The tube is made of a thermoplastic-metal-thermoplastic-thermoplastic-metal-thermoplastic laminate.

U.S. Pat. No. 4,705,194 entitled “Toothbrush holder attachment for toothpaste” in the name of Joseph Judge, Published on Nov. 10, 1987 consists of a non-collapsible toothpaste tube on which the toothbrush is mounted to form an integral part.

U.S. Pat. No. 5.975.361 entitled “Winding and locking device for collapsible tubes” owned by Richard N. Corrow published on Nov. 2, 1999, describes a sealed system in the lower part of the tube by means of an additional grooved piece.

U.S. Pat. No. 6,056,159 entitled “Holder for full or folded collapsible tubes” in the name of Robert Wesley Layer Published on May 2, 2000, mentions a dispenser for a collapsible tube which consists of a firm base which has a V-shaped truncated section to the centre, where the collapsible tube is placed in such a way that it stays in a vertical position.

U.S. Pat. No. 6,415,479 entitled “Clip for squeezing tubes” in the name of Nathan Steinberg Publisher on Jul. 9, 2002, describes a tube which carries joined to the lower part a section in the form of a clip which may be permanent or removed and allows the product to come out extruded.

In polyethylene collapsible tubes, PVC tubes and laminates heat-sealing is used, fusing material with temperature on both sealing bars, allowing the sealing of thick packaging which must keep its contents hermetically packed. This adapts itself to any sealing need for flexible materials at that level, as illustrated in FIGS. 2 a), 2 b) y 2 c).

Patent Application EPO No. 656,855 B1 and U.S. Pat. No. 5,649,648 of Jul. 22, 1997, in the name of Henkel Kommandltgesellschaft, uses a sealing system which consists of a removable plug inserted in the lower part of an aluminium tube like a button to allow the fluid in the tube to come out. The system is applied to collapsible tubes of rigid material since the pressure for the sealing is exerted on the tube.

SUMMARY OF THE INVENTION

The object of this Patent Application for an Utility Model is a Sealing System for Collapsible Tubes and Machine which consists of a plug composed of two sections which are placed in the lower part of the tube so that the tube remains vertical during storage and use, always keeping the shape of the tube, since the sealing pressure is exerted on the plug and the ring.

Another object of this invention is to improve the process of plugging tubes with low-cost technology.

Another object of the invention is to present a Machine or Tube-Holder specifically for use in the sealing system.

The Sealing System for Collapsible Tubes and Machine, object of this Patent Application for a Utility Model has the following advantages:

-   -   The collapsible tube is kept vertical during storage and use,         always keeping its shape due to the sealing system which uses         the plug and ring.     -   The plug is made of inert non-reactive raw materials and is         therefore atoxic, and it does not alter the taste or any other         sensory feature of the liquids in contact with it.     -   The plug is not affected by galvanic, electrolytic or bacterial         corrosion. It is characterised by offering excellent resistance         to attacks of all types of chemical product or reagent. This         resistance is based on its characteristic that it is not polar.     -   The sealing system is used in collapsible tubes of rigid,         semi-rigid and soft material since the pressure the machine         exerts is on the plug and the ring, and it can be applied to         various kinds of industry such as glues and adhesives,         pharmaceuticals, cosmetics, foods etc.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1A-1D are partial perspective views of the sealing system for prior art aluminium collapsible tubes.

FIGS. 2A-2C are partial perspective views of the heat-sealing system used for plastic collapsible tubes (FIG. 2 a) and laminates (FIG. 2 b).

FIG. 3 is an elevational view of an embodiment of the Sealing System for Collapsible Tubes of the present invention.

FIG. 4 is an elevational view of an embodiment of the Plug (1) of the Sealing System of the present invention.

FIG. 5 is an elevational view of an embodiment of the Ring (2) of the Sealing System of the present invention.

FIG. 6 is an elevational view of an embodiment of the Machine or Tube-Holder (7) used in the Sealing System for Collapsible Tubes of the present invention.

FIG. 7 is a partial cross-sectional view of the assembly of the Sealing System for Collapsible Tubes, with a collapsible tube therein, of the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT

While the present invention is susceptible of embodiment in various forms, there is shown in the drawings a number of presently preferred embodiments that are discussed in greater detail hereafter. It should be understood that the present disclosure is to be considered as an exemplification of the present invention, and is not intended to limit the invention to the specific embodiments illustrated. It should be further understood that the title of this section of this application (“Detailed Description of the Illustrative Embodiment”) relates to a requirement of the United States Patent Office, and should not be found to limit the subject matter disclosed herein.

This Patent Application for an Utility Model refers to a Sealing System for Collapsible Tubes and Machine, comprising, as shown in FIG. 3, a) A plug (1); (b) a ring (2); (c) a collapsible tube (3); and (d) Machine or Tube-Holder (7).

Referring to the drawings, the Plug (1) is a cylindrical body, having on the upper part a small circular tab (4), a central section (5) or plug proper, which is a hollow, conical trunk (see FIG. 4 a) or a hollow cylinder (FIG. 4 b), a lower section (6) which is a solid conical trunk or cylinder.

The principal function of the Plug (1) is to prevent the product from leaking out and to maintain the pressure exerted by the Ring.

The part of the Plug (1) which is introduced into the collapsible tube (3), has the external shape of a cone calculated in accordance with the deformation that the tube (3) can support; this shape provides better sealing and a tighter fit to the Ring (2) which internally has the same degree of tapering.

The walls of the plug (1) have a thickness that varies from 2 mm to 4 mm, designed to reduce the permeability allowed by the material much more thus guaranteeing the quality of the product and a longer useful life.

The dimensions of the plug (1) depend on the diameter of the tube and vary from an outside diameter of 12 mm and 15 mm, a total height of 11 mm-12 mm; the hollow central section (5) being 7 mm-8 mm in diameter and 6 mm-7 mm high; and the tab (4) 2 mm high by 13,5 mm in diameter.

The thickness of the plug (1) is designed to support pressures of 2000 kPa-4000 kPa in order to guarantee excellent sealing of the tube. (3).

The plug (1) is designed to facilitate manufacture and to avoid problems arising in the process of injection, such as deformation, contraction and shakeout.

The plug (1) is designed to facilitate the placing of the same in the sealing process.

The thickness of the ring wall (2) is 1-3 mm; height of 8-9 mm and diameter of 16-17 mm depending on the diameter of the tube and it is designed to support working pressure for more than 10 years at a temperature of 20° C.; as seen in the FIG. 5.

The principal function of the ring (2) is to support the pressure exerted by the plug (1) on the walls on the collapsible tube (3).

The inside of the ring (2) has the same taper as the plug (1) to guarantee the best possible seal.

In destructive testing the ring (2) supported pressure of 2000 kPa with no observable change or failing and cracks appeared at 3500 kPa.

The working pressure of the ring (2) is less than 550 kPa.

The ring (2) is designed to facilitate manufacture and avoid the problems that occur in injection, such as deformation, contraction and shakeout.

The ring (2) is designed to facilitate the placing of the same in the sealing process.

The plug (1) and the ring (2) support temperatures of −5° C.-100° C., depending on the material of which they are made.

The plug and the ring are made by injection of PP polypropylene, which is a commercial thermoplastic material, semi crystalline and semi-opaque-white. PP polypropylene is linear polyolefin with catalysts to control ester-regularity so that the polypropylene is usually predominantly isotactic with hardness and heat resistance superior to HD polyethylene. Polypropylene copolymers have better resistance to impact. Polypropylene, like the polyethylenes, has good chemical resistance but weak resistance to UV rays (unless previously stabilised or protected).

The polypropylene copolymers are used in making tubing, ships' hulls, seats and parts for cars, plugs and lids for containers etc.

The properties of poliproylene used for this invention are: Electrical: Dielectric Constant at 1 MHz 2.2 a 2.6 Dissipation Factor at 1 MHz 0.0003 a 0.0005 Dielectric Resistance (kV mm⁻¹) 30 a 40 Surface resistivity (Ω/s) 10¹³ Volume resistivity at ° C. (Ω · cm) 10¹⁶ a 10¹⁸ Physical: Water absorption - Equilibrium (%) 0.03 Density (g/cm³) 0.90 Refractive index 1.49 Oxygen limit index (%) 18.00  Flammability Combustible Resistance to UV Acceptable Mechanical: Stretching to breaking point (%) 150-300 Friction coefficient 0.1-0.3 Hardness - Rockwell  R80-R100 Traction module (GPa) 0.9-1.5 Abrasion resistance (mg/1000 cycles) 13-16 Traction resistance (MPa) 25-40 Izod Impact resistance (J m⁻¹)  20-100 Thermal: Specific heat (J K⁻¹ kg⁻¹) 1700-1900 Heat expansion coefficient (×10⁻⁶ K⁻¹) 100-180 Conductivity at 23° C. (W m⁻¹ K⁻¹)  0.1-0.22 Maximum working temperature (° C.)  90-120 Minimum working temperature ° C. −10-−60 Hot deflection temperature 100-105 −0.45 MPa (° C.) Hot deflection temperature 60-65 −1.8 MPa (° C.) Chemical resistance: Acids - concentrated Good Acids - diluted Good Alkalis Good Alcohols Good Cetones Good Fats and oils Acceptable Halogens Bad Aromatic hydrocarbons Acceptable

Permeability tests show that resistance to permeability of polypropylene is significantly increased in the stretching process, due to the alignment of molecular chains.

The results show that polypropylene plug obtained by injection are more resistant to the passage of oxygen.

A Machine or Tube-Holder (7) is required for the process for sealing the collapsible tubes; it is made in accordance with the size of the collapsible tubes (3); commercially there are tubes of 12,8 mm, 15,8 mm, 19 mm, 20,7 mm, 22 mm, 25,4 mm, 26,6 mm, 28,4 mm y 31,7 mm diameter and the length of the tube varies from 50 mm to 200 mm.

The collapsible tubes (3) used in this invention are of rigid, semi-rigid and soft materials.

The Tube-Holder (7) is made of steel and teflon, brass and teflon; stainless steel and teflon, depending on the use to be made of the container.

The Tube-Holder (7) has five parts as seen in FIG. 6, as follows: a) a steel spring (8); b) a steel, stainless steel or brass fixing housing (9); c) a steel, stainless steel or brass base to hold the spring (10); d) a teflon base to support the tube (11); e) a Teflon guide to fit the tube (12).

The spring (8) is a compression spring designed especially to the dimensions of the collapsible tube (3).

The functions of the spring (8) are to hold the base support for the tube (11), joined to the guide to fit the tube (12); to be compressed in order to allow the movement of the collapsible tube (3) simultaneously when the plug (1) is being introduced into it and to expel the tube (3) when the sealing process is complete.

The fixing housing (9) enables all the other elements to be anchored down and supported.

The base for holding the spring (10) supports the compression forces exerted on the spring and protects it.

The base supporting the tube (11) supports the collapsible tube (3) and supports the forces exerted in the process of placing the plug. (1).

The guiding to fit the tube (12) directs the movement of the collapsible tube (3) and holds the ring (2) to plug and completely seal the collapsible tube (3).

Assembly Process

The Sealing System for Collapsible Tubes, object of this patent, is assembled as can be seen in FIG. 7, as follows:

First, the ring (2) in placed in the Tube-Holder (7), then the collapsible tube (3) is placed in the Tube-Holder (7).

The product to be filled is introduced, and the plug (1) is placed in the collapsible tube (3) and force is applied to the plug until it makes contact with the ring (2).

The collapsible tube (3) is removed from the Tube-Holder (7). 

1. A Sealing System for Collapsible Tubes and Machine, wherein the system has a plug (1) and a ring which are placed at the bottom end of a collapsible tube (3), by a Machine or Tube-Holder (7).
 2. A Sealing System for Collapsible Tubes of claim 1 wherein the plug (1) is a cylindrical body with a small circular tab (4) at the top, a central section (5) or plug proper, which is a hollow conical trunk or hollow cylinder; and a lower section (6) which is a conical trunk or solid cylinder.
 3. A Sealing System for Collapsible Tubes of claim 1 wherein the walls of the plug (1) have a thickness of 2-4 mm and the dimensions of the plug (1) depend on the diameter of the tube namely: outside diameter of 12-15 mm, total height of 11-12 mm; with the hollow central section (5) 7-8 mm diameter and height of 6-7 mm, and the tab (4) 2 mm high and 13.5 mm diameter.
 4. A Sealing System for Collapsible Tubes of claim 1 wherein the ring (2) has a thickness of 1-3 mm, a height of 8-9 mm and a diameter of 16-17 mm, depending on the diameter of the tube.
 5. A Sealing System for Collapsible Tubes of claim 1 wherein the sealing system is applied to rigid, semi-rigid and soft collapsible tubes.
 6. A Sealing System for Collapsible Tubes of claim 1 wherein the Machine or Tube-Holder (7) has five parts, as follows: a) a spring (8); b) a fixing housing (9); c) a base to hold the spring (10); d) a base to support the tube (11); e) a guide to fit the tube (12).
 7. A Sealing System for Collapsible Tubes of claim 5 wherein the spring (8) is a compression spring which holds the base to support the tube (11), joined to the guide to fit the tube (12); and then, it compresses to displace the collapsible tube (3) simultaneously when introducing the plug (1) into itself and finally, it expels the tube (3) when the sealing process is complete.
 8. A Sealing System for Collapsible Tubes of claim 1 wherein the guide to fit the tube (12), directs the movement of the collapsible tube (3) and holds the ring (2) to plug and completely seal the collapsible tube (3). 